[PATCH 3.19 069/101] cpuidle: remove state_count field from struct cpuidle_device

Greg Kroah-Hartman
2015-04-17T13:56:43Z

From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

commit d75e4af14e228bbe3f86e29bcecb8e6be98d4e04 upstream.

Thomas Schlichter reports the following issue on his Samsung NC20:

"The C-states C1 and C2 to the OS when connected to AC, and additionally
provides the C3 C-state when disconnected from AC. However, the number
of C-states shown in sysfs is fixed to the number of C-states present
at boot.
If I boot with AC connected, I always only see the C-states up to C2
even if I disconnect AC.

The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count
setting). It removes the update of dev->state_count, but sysfs uses
exactly this variable to show the C-states.

The fix is to use drv->state_count in sysfs. As this is currently the
last user of dev->state_count, this variable can be completely removed."

Remove dev->state_count as per the above.

Reported-by: Thomas Schlichter <thomas.schlichter@web.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/cpuidle/cpuidle.c | 3 ---
drivers/cpuidle/sysfs.c | 5 +++--
include/linux/cpuidle.h | 1 -
3 files changed, 3 insertions(+), 6 deletions(-)

--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -297,9 +297,6 @@ int cpuidle_enable_device(struct cpuidle
if (!dev->registered)
return -EINVAL;

- if (!dev->state_count)
- dev->state_count = drv->state_count;
-
ret = cpuidle_add_device_sysfs(dev);
if (ret)
return ret;
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -401,7 +401,7 @@ static int cpuidle_add_state_sysfs(struc
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);

/* state statistics */
- for (i = 0; i < device->state_count; i++) {
+ for (i = 0; i < drv->state_count; i++) {
kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
if (!kobj)
goto error_state;
@@ -433,9 +433,10 @@ error_state:
*/
static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
{
+ struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
int i;

- for (i = 0; i < device->state_count; i++)
+ for (i = 0; i < drv->state_count; i++)
cpuidle_free_state_kobj(device, i);
}

--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -68,7 +68,6 @@ struct cpuidle_device {
unsigned int cpu;

int last_residency;
- int state_count;
struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
struct cpuidle_driver_kobj *kobj_driver;